Is it true that certain foods are good for a strong immune system? Let’s find out the answer.

It should be very clear that there’s no way to “boost” your immune system. Kristin Kirkpatrick, a registered dietitian at Cleveland Clinic, says, “It’s better to say enhancing immunity.”

Innate and acquired are the two facets of the human immune system.

Your first line of defense is the innate immune system that starts working the moment you’re born, based on your mother’s living style when you were in the womb.

Fighting off infections, these cells go to work immediately. After four to seven days, white blood cells and proteins — antibodies — targeted to a specific pathogen will be mobilized to fight the infection if the innate system does not do its work. Leading to body inflammation, this immune response may result in fever and other uncomfortable reactions.

Your body’s immune system becomes stronger with the right food you eat. According to Kirkpatrick, a healthy diet, along with other things like sleep and stress management help contribute to a robust immune system.

Avoid excess sugar by eating a diet of 80 percent real food as excessive sugar slows down immune function. Kirkpatrick says good food diversity and colorful plants are going to be key factors to a healthy body.

Nutritionists see the human body’s immune system as an imported luxury car. Experts say some of us treat our vehicles better than our bodies.

Vitamin A: As evidence proves, vitamin A enhances immune response a way that surprises researchers. Including natural killer cells, retinoic acid supports the innate immune system. Remember that the epithelial cells and mucous layer act as defensive barriers in the lungs and intestines.

Best sources for Vitamin A:
Alison Brown, a nutritional researcher says, “Carotenoids are found in plant-based sources of vitamin A and retinoids are in food like liver or egg yolks. Cod liver oil is a potent source of the latter. Orange or golden foods like sweet potatoes, carrots, egg yolks, and cantaloupe melon are rich in vitamin A and so are spinach and broccoli.

Folate
Kirkpatrick says Folate, also known as B9, helps send signals to the natural killer cells, which are critical for immune response. Folate also helps form and repair DNA.

Best sources: For Folate, Lentils, and other legumes, like asparagus are good sources, so are leafy greens like broccoli sprouts, Brussels sprouts, and beets, along with beef and chicken liver.

Vitamin C
To do many beneficial things for the body, vitamin C is a powerful antioxidant. Vitamin C supports protective epithelial cells and killer cells’ work, according to a 2017 research paper that explored vitamin C’s impact on immunity. To help immune cells, vitamin C is very important to clean up the infected areas. Anitra Carr, a professor at the University of Otago New Zealand, says, “Vitamin C deficiency results in impaired immunity and higher susceptibility to infections.” Her research paper says eating a diet high in vitamin C is the best protection.

Best sources: All citrus fruits from lemons and tangerines to oranges and grapefruits have an ample amount of vitamin C. So eat them whether fresh, canned or frozen.

Vitamin D: The sunshine vitamin, is critical to optimal immune function. It helps fight off viruses and infections by sending signals of action in the cells. Low vitamin D levels are lethal as they are associated with higher rates of sepsis, MRSA, and hepatitis C. At least 30 ng/ml of vitamin D in the bloodstream can prevent or blunt the severity of pneumonia and respiratory infections.

At the Medical University of South Carolina, researchers currently are studying whether supplementing with vitamin D can lessen the severity of COVID-19 infections. The researchers are hoping D3 supplementation could improve the immune system of African Americans and the elderly in care homes, who are often vitamin D deficient and are especially vulnerable.

Best sources: D3 supplements are the key source of vitamin D. Salmon, other fatty fish, and egg yolks offer vitamin D’s small amounts. Sun exposure is an easy way to synthesize vitamin D unless you have dark skin.

Vitamin E: Acting as an antioxidant, this nutrient protects cells from damage and supports the creation and action of T cells, a type of white blood cell that’s important for the immune system. A Tufts University’s 2019 research paper says that “Although the deficiency is rare, vitamin E supplementation above current dietary recommendations has been shown to enhance the function of the immune system and reduce risk of infection, particularly at old age.”

Best sources: Almonds, sunflower seeds, and most seeds are abundant in vitamin E. You can also find it in avocados, spinach, mangoes, butternut squash, and cooking oils like safflower and olive.

Zinc: A micronutrient that helps people recover faster from colds. Zinc winds up in fizzy vitamin drink powders and throat sprays. Two different meta-analyses proved that people who took zinc lozenges (75-100 mg) significantly reduced their cold durations as long as the zinc was taken early in the cold’s lifecycle.

Best sources: Find zinc naturally in beans, legumes like lentils, and a range of nuts from almonds and peanuts to pumpkin seeds. Fatty fish like salmon and mackerel are good sources of zinc, too.

Selenium
Like Zinc, Selenium is a trace mineral but it’s less well-known. Selenium is required by proteins called selenoproteins that help kick off the immune response to fight invading germs or viruses.

Best sources: Experts say, “The main source of selenium in any decent amount is Brazil nut.